NAC459.829. Waste containing mixture of radionuclides: Computation of classification.

If the waste contains a mixture of radionuclides, the classification must be determined by dividing each nuclide’s concentration by its limit in the appropriate table and adding the resulting quotients. In computing this sum, all limits must all be taken from the same column of the same table. The sum of the fractions for the column must be less than 1.0 if the class of the waste is to be determined by that column. For example, a package of waste contains Sr-90 in a concentration of 50 Ci/m³ and Cs-137 in a concentration of 22 Ci/m³. Since the concentration of one of the nuclides exceeds the value in Column 1 of Table 2, they must be compared to the values in Column 2. The computations of the fractions are: for Sr-90, 50/150 = 0.33; for Cs-137, 22/44 = 0.5. The sum of the fractions is: 0.33 + 0.5 = 0.83. Since the sum is less than 1.0, the waste is Class B.

     (Added to NAC by Bd. of Health, eff. 4-27-84)